MOSCOW (Sputnik) — According to the Ekathimerini newspaper, the incident took place at a check point in Promachonas on the Greek-Bulgarian border.
The Bulgarian authorities have detained the truck drivers involved in the incident.
Greek farmers have been using tractors to block the main highways, checkpoints and customs points on the country's borders with Turkey, Bulgaria and Albania since January, causing long delays that have particularly affected freight traffic.
Bulgaria condemned the move by Greek farmers to close crossings and said Athens had failed to comply with its obligations under EU law.
Earlier this month, Bulgaria asked the European Commission to help restore the free movement of goods across the country’s border with Greece.